Re-land: Add callgrind collection to Timer #44717

[robieta]

Test plan: The unit test has been softened to be less platform sensitive.

[robieta]

CC @ngimel @ezyang

[dr-ci]

💊 CI failures summary and remediations

As of commit 6e9ad61 (more details on the Dr. CI page):

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✅ None of the CI failures appear to be your fault 💚

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• 1/1 broken upstream at merge base ce9df08 since Sep 30

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🚧 1 ongoing upstream failure:

These were probably caused by upstream breakages that are not fixed yet:

• pytorch_macos_10_13_py3_build since Sep 30
  • 🔁 rerun

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This comment has been revised 1 time.

[facebook-github-bot]

@robieta has imported this pull request. If you are a Facebook employee, you can view this diff on Phabricator.

[ezyang]

Huh, did we miss this last PR because slow tests aren't run by default? @seemethere do target specifiers work yet? O/W you can just push a synthetic PR to ci-all/ASDFAsdf branch to trigger all tests.

[facebook-github-bot]

@robieta merged this pull request in 2b13d94.

[xkszltl]

Want to bring up an issue with this PR:
The sourceware.org repo is extremely slow when accessing from China, almost unusable.
I have a local git mirror so it won't be too bad for me after the initial setup, but could be an terrible experience for others.

Should we ask for pre-built binary from distro, instead of having it as a submodule?

[ezyang]

cc @malfet we should just go back to vendoring the headers directly

[malfet]

@ezyang we can totally do that, or simply create a mirror on github...

[xkszltl]

Actually I tried creating a mirror on GitHub just to reroute through its CDN, but somehow I end up with VCS detection error.
GitLab works.

[robieta]

I need to do a follow up PR to address a couple papercuts anyway, which I was going to do today. Do we have a preference between vendoring the headers vs. a mirror repo?

[ezyang]

Header vendor seems much better to me

[malfet]

Following PR should embed the headers: #45914